[TIPS] Refactoring - Clean Code - Tip 7 - Encapsulate Data and Behavior in Classes

Refactoring Tip 7: Encapsulate Data and Behavior in Classes

Junior: Might use procedural programming without leveraging classes.
Senior: Uses classes to encapsulate related data and behavior, following principles of Object-Oriented Programming (OOP).

Encapsulating data and behavior in classes is crucial for writing organized and maintainable code. Here's an example to illustrate the difference between how a junior and a senior developer might approach this principle.

Example 1: Handling User Data

Junior Developer's Approach

A junior developer might use procedural programming to handle user data:

users = []

def add_user(name, age): users.append({'name': name, 'age': age})

def get_user(name): for user in users: if user['name'] == name: return user return None

def update_user(name, age): for user in users: if user['name'] == name: user['age'] = age

# Usage add_user('Alice', 30) add_user('Bob', 25) print(get_user('Alice')) update_user('Alice', 31) print(get_user('Alice'))

Senior Developer's Approach

A senior developer would use classes to encapsulate user data and behavior:

class User: def __init__(self, name, age): self.name = name self.age = age

def update_age(self, age): self.age = age

class UserManager: def __init__(self): self.users = []

def add_user(self, name, age): self.users.append(User(name, age))

def get_user(self, name): for user in self.users: if user.name == name: return user return None

def update_user(self, name, age): user = self.get_user(name) if user: user.update_age(age)

# Usage user_manager = UserManager() user_manager.add_user('Alice', 30) user_manager.add_user('Bob', 25) print(vars(user_manager.get_user('Alice'))) user_manager.update_user('Alice', 31) print(vars(user_manager.get_user('Alice')))

Example 2: Managing a Library System

Junior Developer's Approach

A junior developer might use procedural programming to manage a library system:

books = []

def add_book(title, author): books.append({'title': title, 'author': author})

def get_book(title): for book in books: if book['title'] == title: return book return None

def remove_book(title): global books books = [book for book in books if book['title'] != title]

# Usage add_book('1984', 'George Orwell') add_book('To Kill a Mockingbird', 'Harper Lee') print(get_book('1984')) remove_book('1984') print(get_book('1984'))

Senior Developer's Approach

A senior developer would use classes to encapsulate book data and library management behavior:

class Book: def __init__(self, title, author): self.title = title self.author = author

class Library: def __init__(self): self.books = []

def add_book(self, title, author): self.books.append(Book(title, author))

def get_book(self, title): for book in self.books: if book.title == title: return book return None

def remove_book(self, title): self.books = [book for book in self.books if book.title != title]

# Usage library = Library() library.add_book('1984', 'George Orwell') library.add_book('To Kill a Mockingbird', 'Harper Lee') print(vars(library.get_book('1984'))) library.remove_book('1984') print(library.get_book('1984'))

Example 3: Processing Orders

Junior Developer's Approach

A junior developer might use procedural programming to process orders:

orders = []

def add_order(order_id, amount): orders.append({'order_id': order_id, 'amount': amount})

def get_order(order_id): for order in orders: if order['order_id'] == order_id: return order return None

def update_order(order_id, amount): for order in orders: if order['order_id'] == order_id: order['amount'] = amount

# Usage add_order(1, 100) add_order(2, 150) print(get_order(1)) update_order(1, 120) print(get_order(1))

Senior Developer's Approach

A senior developer would use classes to encapsulate order data and processing behavior:

class Order: def __init__(self, order_id, amount): self.order_id = order_id self.amount = amount

def update_amount(self, amount): self.amount = amount

class OrderManager: def __init__(self): self.orders = []

def add_order(self, order_id, amount): self.orders.append(Order(order_id, amount))

def get_order(self, order_id): for order in self.orders: if order.order_id == order_id: return order return None

def update_order(self, order_id, amount): order = self.get_order(order_id) if order: order.update_amount(amount)

# Usage order_manager = OrderManager() order_manager.add_order(1, 100) order_manager.add_order(2, 150) print(vars(order_manager.get_order(1))) order_manager.update_order(1, 120) print(vars(order_manager.get_order(1)))

Key Improvements:

Encapsulation: Group related data and behavior into classes, improving organization and maintainability.
Modularity: Encapsulate functionality within classes, making the code easier to understand and extend.
Object-Oriented Principles: Follow OOP principles to create reusable and scalable code.

Encapsulating data and behavior in classes leads to better organization, easier maintenance, and scalability of the codebase. These examples demonstrate how a senior developer's approach to refactoring can lead to more structured and maintainable code.